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| author | Dan Goodliffe <dan@randomdan.homeip.net> | 2022-12-28 13:49:54 +0000 |
|---|---|---|
| committer | Dan Goodliffe <dan@randomdan.homeip.net> | 2022-12-28 13:50:06 +0000 |
| commit | 69acdf6584be2a04094e27b395c50c071b2b15cf (patch) | |
| tree | b9134ccb2087960637c6d7059f51af7fb02c18e3 /lib/stream_support.hpp | |
| parent | No need for the range hack, the shadow box is just centred around the origin (diff) | |
| download | ilt-69acdf6584be2a04094e27b395c50c071b2b15cf.tar.bz2 ilt-69acdf6584be2a04094e27b395c50c071b2b15cf.tar.xz ilt-69acdf6584be2a04094e27b395c50c071b2b15cf.zip | |
Use the existence of .substr(...) to test if a T is stringlike
Diffstat (limited to 'lib/stream_support.hpp')
| -rw-r--r-- | lib/stream_support.hpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/stream_support.hpp b/lib/stream_support.hpp index 5f45cbf..a3565d8 100644 --- a/lib/stream_support.hpp +++ b/lib/stream_support.hpp @@ -8,14 +8,16 @@ #include <sstream> #include <type_traits> +template<typename S> +concept stringlike = requires(const S & s) { s.substr(0); }; template<typename T> concept spanable = std::is_constructible_v<std::span<const typename T::value_type>, T> && ! -std::is_same_v<char, std::decay_t<typename T::value_type>>; +stringlike<T> && !std::is_same_v<std::span<typename T::value_type>, T>; namespace std { template<typename T, std::size_t L> std::ostream & - operator<<(std::ostream & s, const span<const T, L> v) + operator<<(std::ostream & s, const span<T, L> v) { s << '('; for (const auto & i : v) { |